In an increasingly networked world, digital networks deliver a plethora of data services to end-users. For example, end-users may receive video and audio streams over a network, such as a packet-based network. Video streams may include Internet Protocol Television (IPTV), for example, in which digital television signals may be delivered to consumers using the Internet Protocol (IP).
Some data services, including IPTV, may use a multicasting protocol. “Multicasting” generally refers to the delivery of data to a group of destinations. To conserve bandwidth, multicast data may be transmitted once over each link of the network. Data may be replicated when the path to the destinations splits between multiple links. The bandwidth savings using multicasting may be significant.
Networks may use routers, switches, and other network devices for receiving and forwarding multicast data. Such network devices may receive multicast packets through one interface (e.g., port) and may determine which interfaces to forward the packets.